Created attachment 193552[details]
WinDbg backtrace
Both QtWebKit 2.3 and QtWebKit from Qt 5.0.1 crashes on http://gifak.net most of the time right after finishing loading.
You may need to refresh the site few times to reproduce the crash.
I've tried building QtWebKit with --no-force-sse2 and also Qt with -no-sse2, however it didn't help.
I've attached backtrace from Qt 5.0.1.
For the record, the backtrace is not from QtTestBrowser, but QtTestBrowser is also affected.

I first used pre-built Qt 5 from qt-project.org, it is using msvc2010.
Then i tried with Qt 4.8 and QtWebKit 2.3 both built with msvc2010, and also with msvc2008.
The issue is there across the compiler's versions.

At the top of the stack: dst = 0x00000000`000000da
So this might be a failing malloc, seeing the actual page I can see how that could happen :)
I tried on Linux with trunk and it doesn't crash, so maybe we have a Windows specific leak somewhere.